Touch screens can be categorized into the out-cell touch screen and the in-cell/on-cell touch screen. The out-cell touch screen is composed with an independent touch panel and an independent display panel laminated with each other. The in-cell/on-cell touch screen is to embed the touch control circuit into the display panel to realize the integration of the touch panel and the display panel. The in-cell touch screens can be further categorized into an in-cell touch screen and an on-cell touch screen. The in-cell touch screen is the technology that the touch control circuit is integrated into the liquid crystal pixels. The on-cell touch screen is the technology that the touch control circuit is integrated between the color filter and the polarizer. Compared with the other touch screens, the in-cell touch screen can allow the entire panel to be thinner.
As considering the in-cell touch screen, it is demanded to drive the touch control circuit for realizing the touch control function and the display circuit for realizing the display function respectively to achieve the touch control function and the display function. In the driving method of prior art, the scans to the touch control circuit and the display circuit are generally implemented at the same time. When the touch screen is driven to display, the detection for the touch operations to the touch screen is executed at the same time. However, the mutual interference problem can easily happen when the touch control circuit and the display circuit are functioning at the same time. For instance, when the scan is implemented to the display circuit, the transistor TFT flips, parasitic capacitance can be generated with the multi-touch sensor and coupled to the multi-touch sensor. Accordingly, the precision of the touch sense detection can be influenced; when the scan is implemented to the touch control circuit, the activation signals in the touch control detection operation can be coupled to the voltage level of the display circuit. The voltage level fluctuation of the display circuit can be affected and the image distortion can easily occur.
For solving the mutual interference issue, a scan method is proposed in the prior art that the active area is divided into two parts. In the first scan time section of the scan period, the scan is implemented to the display circuit of the first active area. In the second scan time section of the scan period, the scan to the touch control circuit is implemented for full screen. In the third scan time section of the scan period, the scan is implemented to the display circuit of the second active area. Accordingly, the mutual interference between the two circuits can be solved. However, with such arrangement, the scan to the touch control circuit will not start until the scan to the display circuit of the first active area is accomplished. The scan to the display circuit of the second active area will not start until the scan to the touch control circuit for full screen is accomplished. Thus, the scan time must increase.